<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<style id="ss" type="text/css">

#o {
  height: 65px;
}

</style>
<script type="text/javascript">

function boom()
{
  document.getElementById("ss").disabled = true;
  document.documentElement.offsetHeight;
  document.getElementById("ss").disabled = false;
}

</script>
</head>
<body onload="boom();">

<div style="-moz-column-width: 0;">
  <colgroup></colgroup>
  <div>
    <div id="o" style="float: left;"></div>
    <div style="clear: both;">A B<div style="float: left;"></div></div>
  </div>
</div>

</body>
</html>
